Message-ID: <3300D13E.22CF@pobox.oleane.com>
Date: Tue, 11 Feb 1997 21:06:22 +0100
From: Francois Charton <deef AT pobox DOT oleane DOT com>
Organization: CCMSA
MIME-Version: 1.0
To: Benjamin D Chambers <chambersb AT juno DOT com>
CC: djgpp AT delorie DOT com
Subject: Re: Allegro joystick questions
References: <5dlf2r$sh4 AT organ DOT cs DOT indiana DOT edu> <19970210 DOT 173501 DOT 4967 DOT 0 DOT chambersb AT juno DOT com>
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Benjamin D Chambers wrote:
> 
> >
> >Alternatively, is it possible to get Allegro to work with two
> >joysticks?
> >I mainly ask because I've been writing a small space-flight
> >simulation,
> >which means 6 degrees of freedom, and overloading things with keysyms
> >and
> >the mouse gets awkward.
> Just out of curiosity, what are the 6 degrees of freedom?  I know 5
> (north/south, east/west, up/down, ana/kata, foreward/backward {the last
> two are time, but people seem to like to think of time as a geometric
> dimension <it is, but that gets _very_ confusing>}), but it's VERY hard
> to real-time more than 3 (at least the way I'm thinking).
> 

To locate a point in 3d spae, you need 3 coordinates. But a 
plane/spaceship is a solid, and you have to add three angles for its 
"facing" : 
1 left/right angle, the direction the plane goes
1 up/down angle: whether it climbs or goes down
1 other angle : is it "flying" normally, wings parallel to the ground, or 
"upside down", or...

That is six position coordinates.

If you want to add velocity, then you will need three more coordinates 
(in the general case), and three more angles if the plane can be tumbling 
on itself...

Francois